922 resultados para animal feed


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The effect of feeding 0, 4, 8 and 16% rapeseed oil from 12-42 days of age was studied in broiler chickens on performance, digestibility of nutrients, and development of gastrointestinal tract, protein and energy metabolism. Thirty six female chickens (Ross 208) with initial body weight average 246 g were allocated to the four groups and kept pair-wise in metabolism cages. The chickens were fed similar amounts of metabolisable energy (ME) per day and similar amounts of essential amino acids relative to ME by adjusting with crystalline amino acids. The chickens were subjected to four balance periods each of five days with two 24 h measurements of gas exchange in two open-air-circuit respiration chambers inserted on the second and third day of each period. The addition of rapeseed oil increased the amount of gutfill indicating a reduced rate of passage and causing a hypertrophy of the gastrointestinal tract. There was a positive effect on feed utilisation as well as on digestibility especially of dietary fat together with higher utilisation of protein with addition of rapeseed oil. The partial fat digestibility of rapeseed oil estimated by regression was 91.1% and the partial metabolisability (ME/GE) of the rapeseed oil was estimated to 85% yielding an apparent metabolisable energy value of 34.30 MJ/kg.

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Using heterogeneous vegetation in alpine grassland through grazing is a necessary component of deintensification of livestock systems and conservation of natural environments. However, better understanding of the dynamics of animal feeding behaviour would improve pasture and livestock grazing managements, particularly in the early part of the spring season when forage is scarce. The changes in behaviour may improve the use of poor pastures. Then, enhancing management practices may conserve pasture and improve animal productivity. Grazing behaviour over 24 In periods by yaks in different physiological states (lactating, dry and replacement heifers) was recorded in the early, dry and later, germinating period of the spring season. Under conditions of inadequate forage, the physiological state of yaks was not the primary factor affecting their grazing and ruminating behaviour. Forage and sward state affected yaks' grazing and ruminating behaviour to a greater extent. Generally, yaks had higher intake and spent more time grazing and ruminating during the later part of the spring season, following germination of forage, than during the earlier dry part of the season. However, the live weight of yaks was less during pasture germination than during the early dry part of the season because the herbage mass is low, and the yaks have to expend much energy to seek feed at this particular time. (c) 2007 Elsevier B.V. All rights reserved.

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Stable carbon and nitrogen isotope ratios were measured in plant populations and plateau pikas to determine enrichment in stable isotopes of three alpine meadow ecosystems at different elevations in the Qinghai-Tibet Plateau. The results indicated that stable carbon isotope signatures of plant populations at the three locations showed significant variations, delta C-13 of plant populations showed an enrichment of 0.86 parts per thousand per 1000 in over the linear proportion of the altitudinal response, while stable nitrogen isotopes showed no apparent difference. The stable nitrogen isotopes of plateau pikas became significantly isotopically heavier along altitudinal gradients and showed an enrichment of 3.17 parts per thousand/km. Stable carbon isotopes showed no significance, however, and the enrichment of 0.448 parts per thousand/km. delta C-13 and delta N-15 in plateau pikas were not significantly correlated. There appeared to be segregation between the metabolism of stable carbon and nitrogen isotopes of plateau pikas. Variances in metabolic rate at lower water availability and temperatures are presumed to be the main cause of enrichment of stable nitrogen isotopes along altitudinal gradients. Attention should be paid to construct trophic positions and to trace food chain information based oil an isotopic enrichment model.

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A feeding trial A as conducted at the farm of Qinghai Academy of Animal and Veterinary Science, Xining, China during 1996 - 1997 with three dry yak cows (initial body weight 163 - 197 kg, age 5 - 6 years) by using 3 x 3 Latin Square Design to determine the effect of levels of feed intake on digestion, nitrogen balance and purine derivative excretion in urine of yak cows. The animals were fed oat hay (nitrogen 13.5 g/kg dry matter (DM), metabolisable energy 8.3 MJ/kg DM), i.e., 0.3, 0.6 and 0.9 of voluntary intake (VI). Each intake treatment lasted for 17 days and the samples (feeds, faeces and urine) were collected during last 7 days of each period. The results indicate that digestibility of dietary DM, OM, NDF and ash declined when intake levels increased from 0.3 to 0.9 VI [DM, from 66.1% to 59.1% (P < 0.05); OM, from 68.1% to 59.9% (P < 0.05); NDF, from 62.1% to 54.3% (P < 0.05); and ash, from 33.9% to 11.8% (P < 0.05)]. Around 0.10 g N/kg W-0.75 was deficient daily in yak cows at 0.3 VI, and positive N balances were observed at 0.6 and 0.9 VI. Intake levels significantly (P < 0.05) affected total PD excretion in yak urine. The proportion of allantoin increased (P < 0.05) and uric acid decreased (P < 0.05) as intake level of feed increased. (C) 2004 Elsevier B.V. All rights reserved.

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Equipe multidisciplinar: Ademir Hugo Zimmer, CNPGC; Armindo Neivo Kichel, CNPGC; Bela Grof; Carlos Maurício Soares de Andrade; Celso Dornelas Fernandes, CNPGC; Francisco Assis Rolim Pereira; Haroldo Pires Queiroz, CNPGC; Hortência Maria Abranches Purcino; Jaqueline Rosemeire Verzignassi, CNPGC; José Alexandre Agiova da Costa, CNPGC; José Marcelino Sobrinho (in memorian); José Marques da Silva, CNPGC; José Raul Valério, CNPGC; Leônidas da Costa Schalcher Valle; Manuel Cláudio Motta Macedo, CNPGC; Maria José D´Ávila Charchar; Maria do Socorro Bona Nascimento; Marta Pereira da Silva; Rosângela Maria Simeão Resende; Roza Maria Shunke. Histórico e descrição da cultivar. Principais atributos do estilosantes-campo-grande. Fixação biológica de nitrogênio e valor nutritivo. Desempenho animal. Ssutentabilidade de sistemas. Adaptação ao clima. Exigência de solo e adubação. Estabelecimento do estilosantes-campo-grande. Preparo da área para semeadura. Preparo mínimo ou plantio direto. Semeadura. Manejo de plantas daninhas nas pastagens consorciadas com o estilosantes-campo-grande. Manejo do pastejo para o estabelecimento do consórcio. Manejo da pastagem visando à persistência do consórcio. Pragas. Doenças. Outros usos do estilosantes-campo-grande. Uso correto do estilosantes-campo-grande.

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Os programas de colonização na Amazônia tem chamado atenção de cientistas, autoridades e ambientalistas para o impacto ambiental causado por desmatamentos e queimadas na faixa de fronteira agrícola. O extrativismo vegetal tem sido merecedor de grande atenção por parte destes grupos, mas pouca ênfase tem sido dada ao extrativismo animal. A forma como este é praticado pelas populações ribeirinhas, indígenas e de seringueiros já foi objeto de alguns estudos; porém, os conhecimentos disponíveis sobre extrativismo animal em projeto de colonização em área de fronteira agrícola são inexistentes. Se, o extrativismo animal é pouco conhecido é ainda menos estudado e monitorado quanto ao impacto que exerce sobre a composição e estrutura dos povoamentos e populações faunísticas. Este tópico merece uma avaliação criteriosa, pois a caça é uma atividade tradicional na vida das populações rurais brasileiras, destinando-se principalmente à subsistência das mesmas. Em áreas de fronteira agrícola, onde aproximadamente 70% dos colonos são originários de outros ecossistemas, pouco se sabe sobre o extrativismo animal por eles praticados. Este estudo investigou a utilização dos recursos cinegéticos amazônicos por estes colonos e o impacto que estas atividades causam na fauna amazônica. O município escolhido foi Machadinho d´Oeste, em Rondônia, implantado por um projeto de colonização elaborado pelo INCRA e financiado pelo BANCO MUNDIAL, e que, até 1980, possuía sua área toda florestada e intacta. Hoje, cerca de 20 anos após, tem uma interface agrícola e fauna silvestre , com inter-relações específicas, pouco conhecidas e avaliadas. O conhecimento dessas relações possibilita a adoção de medidas corretas para o monitoramento destas áreas que têm estendido suas fronteiras nos últimos anos.

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2004

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A suposição de que prováveis deficiências de elementos minerais nas pastagens de terra firme do Estado do Amazonas estivessem relacionadas com o denominado "mal de secar", doença que ocorre em bovinos, oportunizou a realização do presente trabalho.

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A inviabilidade economica da ensilagem de milho na regiao dos cerrados, devido aos custos muito elevados de insumos necessarios para a sua producao, leva os pecuaristas a ensilar outras forragens. Durante as forragens mais empregadas para ensilagem na regiao, destaca-se o capim-elefante (Pennisetum pupureum Shum) por ser uma graminea de porte grande, de boa producao de massa verde por hectare e bem difundida no meio rural.